Blankenstein Castle was built originally in 1227-1243 by Adolf I, Count of Mark. It was further developed over the course of 200 years by the Counts of the Mark. By 1425, Blankenstein was one of the most important castles in the county. In 1614, shortly before the Thirty Years' War, it was occupied by Spanish troops. From 1637, the castle fell into disrepair so that, in September 1662, Frederick William, Elector of Brandenburg ordered its demolition. Only the tower and parts of the curtain wall remained.
In 1860, the owner of the ruin, the employer, Gustav vom Stein, began to rebuild the castle and established a factory there. The property has belonged to the city of Bochum since 1922, but the town is looking for an alternative due to the costs. From 1957 to 1959, most of the buildings of the 19th century were pulled down, but some still remain.
The tower can still be visited and offers a good view over Bochum and the Kemnader Lake.
References:The stone church of Gamla Uppsala, built over the pagan temple, dates from the early 12th century. Due to fire and renovations, the present church is only a remnant of the original cathedral.
Before the arrival of Christianity in Sweden, Gamla Uppsala was the seat of Swedish kings and a ceremonial site known all over northern Europe. The settlement was home to royal palaces, a royal burial ground, and a great pagan temple. The Uppsala temple, which was described in detail by Adam of Bremen in the 1070s, housed wooden statues of the Norse gods Odin, Thor and Freyr. A golden chain hung across its gables and the inside was richly decorated with gold. The temple had priests, who sacrificed to the gods according to the needs of the people.
The first Christian cathedral was probably built in the 11th century, but finished in the 12th century. The stone building may have been preceded by a wooden church and probably by the large pagan temple.